The present invention relates to a disk cleaner of the type used to remove scars or stains formed on the surface of an information recording disk, such as an optical disk or a photo-electromagnetic disk. More particularly, the present invention relates to a disk cleaner that has a polishing member which is rotated while it is pressed against the surface of a disk to be polished so as to polish the surface of the disk. A disk cleaner according to the present invention is especially suited for polishing a multi-layer DVD disk.
In recent years, various kinds of disks, such as laser disks, compact disks (CDs), CD-ROMs, DVDs, and the like, have been used extensively as information recording mediums for audio/video devices and for computers. If scars or stains are formed on the surfaces of the disks, especially on the recording surfaces, they not only become unsightly, but also it becomes difficult to read out and properly reproduce the recorded information of the portion of the disk where scars or stains are formed.
It is well-known to remove scars or stains formed on the disks manually using a cloth. However, manual cleaning not only takes a lot of work and time, but it is also difficult to satisfactorily remove the scar or stain. Especially, in the secondhand disk shops or libraries were a great number of disks are stored and frequently reshuffled or lent, a lot of work is required for removing scars or stains from the disks. Therefore, there is a need in the secondhand disk shops and libraries to develop a method which makes it possible to mechanically and automatically remove the scars or stains from the disks instead of removing them manually.
In response to such a need, Japanese Patent Unexamined Publication H7-122038 proposes a disk cleaner that has a cylindrical polishing member, which is arranged to be rotated while the end face portion thereof is pressed against the surface (recording surface) of a disk to be polished so as to polish the surface (recording surface) of the disk while the disk is rotated.
There is also proposed in Japanese Patent No. 3007566 a disk cleaner that has a cylindrical polishing member that is rotated while it is pressed against the surface of the disk, with the rotational axis of the polishing member being positioned perpendicular to the surface of the disk. There is also known, as a modification of the aforementioned disk cleaner, another type of disk cleaner, in which a cylindrical polishing member which is rotated while it is pressed against the surface of a disk to be polished, is positioned with its axis of rotation perpendicular to the surface of the disk so as to cause the disk to rotate by a frictional force imposed between the polishing member and the disk surface, thus polishing the surface of the disk (see Japanese Patent Unexamined Publication 2000-11601).
Previously known disk cleaners have the following problems when they are used to polish a DVD. A DVD is constituted by a pair of disk substrates (an upper layer and a lower layer), each being of about half the thickness of a CD (about 0.6 mm), which are joined by means of an adhesive with their recording surfaces facing each other. Therefore, when a DVD is polished using any one of the aforementioned disk cleaners wherein a polishing member is rotated while it is pressed against the surface of the DVD (disk) to be polished after mounting the DVD on a turntable, the surface being polished (the upper layer) of the disk is heated due to the friction between the polishing surface and the polishing member during the polishing operation. In this case, since the DVD is formed of a two-ply adhesively joined structure, the upper layer becomes heated to a higher temperature (the surface temperature becomes about 70xc2x0 C.) than the lower layer, which causes a difference in expansion between the upper layer and the lower layer, thereby giving rise to such problems that the adhered surfaces may be separated from each other and that cracks may be radially generated at the inner peripheral portion (central portion) of the DVD.
The present invention has been made with a view to overcoming the aforementioned problems. It is an object of the present invention, in particular, to provide a disk cleaner which is capable of preventing, as much as possible, the separation of the adhered surfaces and the forming of cracks, even though the disk to be polished is a DVD of a two-ply structure.
The foregoing object is attained, in accordance with the present invention, by a disk cleaner having a polishing member that is rotated while it is pressed against a surface of a disk to be polished to thereby polish the surface of the disk and an air cooling apparatus that cools the disk by causing outside air to flow along the surface of the disk, the air cooling apparatus being incorporated integrally with the disk cleaner.
In a preferred embodiment, the disk cleaner has a main body on which the polishing member is mounted, and the air cooling apparatus is attached to the main body. The air cooling apparatus includes a blower that generates an air flow, which, preferably, is caused to pass generally diametrically across the surface of the disk.
The main body may include a lower housing having an upper plate and an upper housing having a lower plate, the plates being arranged to form a substantially closed space in the main body. A hinge joins the upper housing to the lower housing such that the upper housing is movable away from the lower housing by pivoting about the hinge. A turntable for supporting the disk is disposed in the closed space, and the polishing member is supported in the upper housing and is received in the closed space.
Preferably, the air cooling apparatus is associated with the lower housing, and an air flow generated by the air cooling apparatus is introduced into the closed space from an air inlet port formed in the upper plate of the lower housing, is directed to flow generally diametrically across the disk, and is discharged outside the main body.
The main body may be provided with an air discharging structure for discharging the air that has been used for cooling the disk out of the main body. Advantageously, the air discharging structure is provided with an air cleaner for trapping shavings of the disk and dust of the polishing member.
The rotational axis of the polishing member may be positioned perpendicular to the surface of the disk at the time of polishing the disk so as to cause the disk to rotate in one direction by a frictional force generated between the polishing member and the surface of the disk. In such a design, a present magnitude of load is imposed on the disk for controlling the rotation of the disk in one direction which results from a frictional force between the polishing member and the surface of the disk. For example, a loading fan may be arranged to be driven in association with the rotation of a turntable on which the disk is to be mounted, thereby applying a load to the disk that controls the rotation of the turntable.
In preferred embodiments of a disk cleaner according to the present invention that have been constructed as described above, the flow of outside air produced by the air-cooling apparatus cools the disk so that the temperature rise due to the frictional heating of the disk during the polishing thereof is suppressed. Therefore, even if the disk being polished is a DVD of a 2-ply structure, it is possible to inhibit not only the peeling of the adhered surfaces but also the generation of cracks.
Since the air flow generated by the air cooling apparatus is allowed to flow generally diametrically across the disk which is being rotated, it becomes possible to effectively and uniformly cool the entire region of the disk.
Moreover, the air flow generated by the air cooling apparatus can be utilized as a trapping air flow for trapping the shavings of the disk or the dust of polishing material which will be generated during the polishing of the disk, thereby making it possible to remove the shavings and dust from the periphey of the disk. Thus, it is no longer required to separately install any additional fan for trapping the shavings and dust.